The field of the invention relates generally to gasification plants, and more particularly, to methods and apparatus for improving synthetic gas production with a gasification plant by separating hydrogen sulfide and carbon dioxide from a flow of synthetic gas.
At least some known gasification plants include a gasification system that is integrated with at least one power-producing turbine system, thereby forming an integrated gasification combined-cycle (IGCC) power generation plant. For example, known gasification systems convert a mixture of fuel, air or oxygen, steam, and/or CO2 into a synthetic gas, or “syngas”. The syngas is channeled to the combustor of a gas turbine engine, which powers a generator that supplies electrical power to a power grid. Exhaust from at least some known gas turbine engines is supplied to a heat recovery steam generator (HRSG) that generates steam for driving a steam turbine. Power generated by the steam turbine also drives an electrical generator that provides electrical power to the power grid.
At least some known gasification systems associated with IGCC plants initially produce a “raw” syngas fuel which includes carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), carbonyl sulfide (COS), and hydrogen sulfide (H2S). CO2, COS, and H2S are typically referred to as acid gases. Acid gas is generally removed from the raw syngas fuel to produce a “clean” syngas fuel for combustion within the gas turbine engines.